In an image forming apparatus such as a copying machine, a printer, and a facsimile that uses an electrophotographic process, a latent image formed on a photoreceptor is visualized with toner of a developing device. However, since toner is consumed when the latent image is developed, it is necessary to replenish toner into the developing device. Thus, a toner replenishing device as a powder supply device provided in the apparatus body conveys toner from a toner container as a powder container to the developing device to replenish toner into the developing device. With the developing device that replenishes toner in this manner, it is possible to perform developing continuously. Moreover, the toner container can be detachably attached to the toner replenishing device and is replaced with a new toner container having toner stored therein when the toner stored therein runs out.
As an example of a toner container detachably attached to the toner replenishing device, a toner container which includes a toner storing member that forms a storage unit that storing toner therein, and in which a spiral projection serving as a powder conveyor is provided on a cylindrical inner circumferential surface of the toner storing member is known (see Japanese laid-open Patent Application (JP-A) No. 2003-241496, JP-A 2005-221825, Japanese patent No. 4342958, JP-A No. 2002-202656, JP-A No. 2003-233247, JP-A No. 2009-276659, and JP-A No. 07-261492, for example). In such a toner container, when the toner storing member rotates in a state of being attached to the toner replenishing device, the toner stored therein is conveyed from one end side in the rotation axis direction of the toner storing member to the other end side. The toner is delivered from an opening provided on the other end side of the toner storing member toward the main body of the toner replenishing device.
JP-A Nos. 2009-276659 and 07-261492 each disclose a toner container in which toner stored in a storage unit is conveyed from one end side thereof to the other end side when a toner storing member rotates, and in which a conveying nozzle fixed to a toner replenishing device is inserted from an opening on the other end side of the toner storing member into the storage unit. A toner inlet is provided near a front end in the insertion direction of the conveying nozzle inserted from the opening of the toner storing member into the storage unit, and the conveying nozzle receives the toner in the toner storing member into the nozzle from the toner inlet in a state of being inserted in the toner container and conveys the toner toward the main body of the toner replenishing device. Moreover, the toner container has a nozzle insertion portion in which a nozzle insertion opening for inserting the conveying nozzle is provided in the opening at the other end of the toner storing member. Further, the toner container includes an opening blocking member that blocks the nozzle insertion opening before the conveying nozzle is inserted and opens the nozzle insertion opening when the conveying nozzle is inserted.
The opening blocking member included in the toner container disclosed in JP-A No. 2009-276659 is a shutter member that can slide in the nozzle insertion path provided in the toner container, and is biased by a spring from one end side of the nozzle insertion path to the other end side. In this structure, when the shutter member biased by the spring bumps against the vicinity of the nozzle insertion opening until the conveying nozzle is inserted, the nozzle insertion opening maintains a blocked state. Moreover, when the conveying nozzle is inserted, the front end of the conveying nozzle presses the shutter member so that the spring biasing the shutter member is contracted, whereby the shutter member can move from the other end side of the nozzle insertion path to one end side and the conveying nozzle can be inserted into the nozzle insertion path.
However, in the toner container disclosed in JP-A No. 2009-276659, a spring and an insertion path defining portion that supports the spring and forms a nozzle conveying path are required in addition to the shutter member which is an opening blocking member, and the structure that opens and blocks the nozzle insertion opening becomes complex.
On the other hand, the opening blocking member included in the toner container disclosed in JP-A No. 07-261492 is an elastic sheet member which is formed of a sheet-shaped elastic member and has a slit provided so as to penetrate from one surface to the other surface thereof. In the toner container disclosed in JP-A No. 07-261492, when a conveying nozzle is inserted in the slit of the elastic sheet member provided so as to block the nozzle insertion opening, the elastic sheet member is elastically deformed so that the slit is expanded. By expanding the slit in this way, the conveying nozzle can pass through portion of the nozzle insertion opening blocked by the elastic sheet member and the conveying nozzle can be inserted in the nozzle insertion opening. Since the nozzle insertion opening is opened and blocked by elastic deformation of the elastic sheet member, it is possible to simplify the structure of opening and blocking the nozzle insertion opening as compared to the toner container of JP-A No. 2009-276659.
In the toner container disclosed in No. JP-A 07-261492, in a state where the elastic sheet member is not elastically deformed, the slit is blocked and toner leakage can be prevented. However, when vibration or impact is applied to the toner container while conveying before it is attached to the toner replenishing device, vibration or impact may be transmitted to the elastic sheet member which may be temporarily elastically deformed, and a gap may be provided in the slit. When a gap is provided in the slit even if temporarily, toner in the storage unit may pass through the slit in the elastic sheet member. When toner passes through the slit in the elastic sheet member during conveying of the toner container, this can cause toner leakage.
In the foregoing description, the problem occurring in the toner container that stores toner as powder has been described. However, the same problem can occur in a powder container that stores powder different from toner. That is, the same problem can occur if a powder container includes an elastic sheet member that blocks a nozzle insertion opening when a powder conveying nozzle fixed to a powder conveying device is not inserted, and the elastic sheet member is elastically deformed to allow the powder conveying nozzle to pass when the conveying nozzle is inserted.
Therefore, there is a need to provide a powder container that includes an elastic sheet member that blocks a nozzle insertion opening in which a powder conveying nozzle that delivers powder stored therein to the outside and that can suppress leakage of powder in a state where a powder conveying device is not attached thereto, and to provide an image forming apparatus including the powder container.